Cross connect blocks have been known and used in the telecommunications industry for the purpose of terminating central office cables and matching pairs therefrom with pairs in distribution lines to subscribers. At the point where a cross connect block is used, a large cable from the central office is generally terminated. At this station smaller distribution cables are also connected to cross connect blocks mounted in juxtaposition to the other cross connect blocks permitting the matching of wire pairs of the central office cable with the correct pair to a subscriber. The cross connect blocks permit changes in the phone circuits to be made, they permit tests of the circuits to be made, and transfers can be made. In some installations, the cross connect block permits additional phones to be connected to a given line pair.
Examples of the existing cross connect blocks include U.S. Pat. No. 4,210,378 which uses a screw type binding post to make the connection between one pair of wires and another. One connection is generally a permanent connection to the block. Improvements on this product to make quicker and faster connections are described in U.S. Pat. Nos. 4,431,247 and 4,815,988. Other examples of a different style of cross connect blocks are illustrated in U.S. Pat. Nos. 4,279,460 and 4,789,354. In each of these examples, wire pairs from one line can readily be joined to wire pairs in an adjacent cross connect block by running wires between the contact elements of the two blocks.
In addition to these prior teachings of cross connect blocks and systems of cross connection, the art is replete with patents related to insulation displacement connectors such as U.S. Pat. Nos. 4,341,430, 4,533,196 and U.K. Patent 2,129,630. These references show varying types of telecommunication or electrical connectors wherein the wire is directed into a U-slot in a metal contact element and the contact element displaces the insulation to make resilient pressure contact against the conductor and make electrical connection therewith.
U.S. Pat. No. 4,127,312 and copending application Ser. No. 07/684,323 filed Apr. 12, 1991, and assigned to the assignee of this application, disclose connectors having contact elements for making insulation displacement connection with discreet wires and they teach making connections between different wire pairs. U.S. Pat. No. 4,127,312 teaches the use of contacts disposed at 90.degree. angles with each other such that initially, contact may be made with a discreet wire through the insulation displacement connection portion of the contact and the opposite end of the contact is provided with a tuning fork contact to make electrical contact with the legs of another contact element to join the elements in electrical connection. This patent also illustrates one way to form such a contact, although this construction requires additional space in the connector body and more metal is needed in the contact.
In the cross connect constructions of the prior art, when it is desired to change the position of a wire pair to another terminal block or to change the position of the wires on the same terminal block, it was necessary to disconnect the wire from the connector and make a new connection to a different connector or contact. The present invention provides a plug module joined to two jumper wires and the module can be moved, repositioned, connected and disconnected to a circuit many times and the connection between the wires and the contacts does not have to be changed. They can remain sealed in the plug with the encapsulant surrounding the junction between the wires and contacts.
The present invention further provides a cross connect block wherein the pairs of wires from a cable are joined to a support block and then individual pairs of distribution wires may be joined to the cable. Cross connections (pairs, triples or quads) are run between terminals on the two sides of a distribution frame, or between contacts in a terminal or block. The connector of the present invention affords half tapping or a bridged connection to be made to a circuit without disturbing its continuity. Half tapping affords the use of the same pair of wires from the cable to be directed to additional phones of a particular subscriber.
Further, the connector of the present invention permits stacking of the plugs for the purpose of half tapping or testing the connection to the wire pair from the central office. The plugs of the connector of the present invention also permit the transfer of lines between one wire pair in the cable to another wire pair in a cable without interrupting the continuity of the circuit.
Additionally, the connector of the present invention may advantageously be used with an overvoltage protection circuit. Although such circuits are known for use in cross connect terminals, nothing in the prior art provides for such an overprotection circuit in combination with a detachable jumper, or in the form of a pluggable module which allows further connection of jumper plugs for the above-stated purposes.